Learning Large-Format Lingo: Is 4K a Useful Term?

Walking into a Best Buy and scanning the television section will likely have you admiring rows of screens that are all relatively the same size. Sure, a 55-inch TV generally makes for a better in-home viewing experience than a 31-inch substitute, but ultimately the difference between those two screens is only two diagonal feet. The sizes and shapes of these screens are all roughly within the same ballpark, so to speak. In this context, it’s easy to conceptualize and compare varying display resolutions, like High Definition, 1080p, and 4K. This ease with which customers can assess the resolutions of modern in-home televisions has led consumers to believe large-format display resolutions operate on a similarly simple scale and that meeting a particular resolution standard is critical. Neither assumption is accurate. To give potential customers a better idea of how one of these common terms applies to uncommon displays, let’s examine the usefulness of a term like 4K in the large-format world.

Resolution Indicates Pixel Dimensions

Ultimately all any resolution tells you is pixel dimensions. For example, a 4K display exhibits a resolution of 3840×2160 pixels. That means its horizontal length contains 3840 pixels and its vertical length contains 2160. Multiplying these two numbers gives you the total number of pixels in the display, while dividing the former by the latter will give you the aspect ratio. Below is a chart indicating the standard pixel dimensions of various common display resolutions.

Shorthand Label

Pixels (Horizontally)

Pixels (Vertically)

Pixels (Total)

Aspect Ratio

HD (720p)

1280

720

777,600

16:9

Full HD (1080p)

1920

1080

2,073,600

16:9

4K

3840

2160

8,294,400

16:9

8K

7680

4320

33,177,600

16:9

The reason this standard is called 4K instead of Double HD or 3,840p is simply a product of marketing because, as you can see, a 4K display does not actually involve the number 4,000 anywhere. Instead, 4K displays simply double the pixel dimensions of a Full HD display (and thus quadruple the total number of pixels). The reason a 55-inch 4K TV delivers a sharper picture than a 55-inch HD TV is because it contains four times the number of pixels within the same physical space. Fitting so many more pixels within the same space requires you to fit those pixels closer together. The figure indicating how close these pixels are is called pixel pitch, and it defines the distance between the centers of adjacent pixels. If you increase resolution without decreasing pixel pitch –in other words, if you increase the number of pixels without shrinking the distance between those pixels- the resulting display will be much larger but no sharper. If you decrease pixel pitch without changing resolution –in other words, if you reduce the distance between pixels without altering the number of pixels- the resulting display will be smaller but sharper. If you would like to learn more about pixel pitch, you can find a helpful white paper of ours here.

What all this is to say is that for formalized resolution labels to be of use as a tool for comparison, display size needs to be fairly uniform. Display shape needs to be relatively constant too, since each formal resolution requires a 16:9 aspect ratio. In the custom large-format world where displays are of all different shapes, sizes, and aspect ratios, these terms lose their value as a tool for comparison. A display measuring 4,000 pixels by 2,000 pixels isn’t HD, nor is it 4K. Does that mean it has poor image quality? No, because formal resolution labels do not define image quality; they only define pixel dimensions.

NanoLumens has installed countless displays that don’t even come close to generic pixel dimensions or to the 16:9 aspect ratio, including 360-degree halos, trapezoids, and even simple squares. Each of these display shapes feature spectacular image quality but when asked by customers if they are 4K, we have to say no because technically, they aren’t. But that’s the thing customers misunderstand about HD, 4K, 8K and the related, restrictive terms: they box you in. NanoLumens is all about thinking outside the 16:9 box by giving customers, designers, and architects the freedom to customize displays in whatever shape they feel like, independent of any formalized resolution standards. In fact, we encourage our customers to eschew these types of run-of-the-mill labels. We can of course make displays that meet any resolution standard you may require, but when everyone else has a 16:9 rectangle, you should dream bigger (or wider, or taller, or in a different shape)! So don’t ask whether a manufacturer can create a display that meets the 4K requirements; ask whether they can create a display that meets your requirements. At NanoLumens, our answer will always be yes. To learn more about the 360-degree halo display mentioned earlier in this piece, read the case study here.